Current world number two Rafael Nadal is headed down under to play in the new ATP tournament in Perth.
The 19-time grand slam winner will also join US open runner-up Danill Medvedev, Japan's Kai Nishikori and the USA's Jack Isner.
Joining Spain and Russia in Perth will be Georgia, Russia, Italy and the USA.
Australia will head to Brisbane drawn in Group F with Germany, Greece and Canada.
The ATP tournament replaces the now-defunct Hopman Cup.
More than $22 million in prize money and ATP ranking points will be on the line for the inaugural tournament, which will kick off the 2020 world tennis season.
A total of 19 teams have been confirmed, with the final five to be decided in November.